[PATCH] sanitize svc_export_parse()

clean up the exit paths, get rid of nameidata

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 35 insertions, 42 deletions

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 9dc036f18356..2fa61f003fff 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -500,35 +500,22 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
         int len;
         int err;
         struct auth_domain *dom = NULL;
-        struct nameidata nd;
-        struct svc_export exp, *expp;
+        struct svc_export exp = {}, *expp;
         int an_int;
 
-        nd.path.dentry = NULL;
-        exp.ex_pathname = NULL;
-
-        /* fs locations */
-        exp.ex_fslocs.locations = NULL;
-        exp.ex_fslocs.locations_count = 0;
-        exp.ex_fslocs.migrated = 0;
-
-        exp.ex_uuid = NULL;
-
-        /* secinfo */
-        exp.ex_nflavors = 0;
-
         if (mesg[mlen-1] != '\n')
                 return -EINVAL;
         mesg[mlen-1] = 0;
 
         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-        err = -ENOMEM;
-        if (!buf) goto out;
+        if (!buf)
+                return -ENOMEM;
 
         /* client */
-        len = qword_get(&mesg, buf, PAGE_SIZE);
         err = -EINVAL;
-        if (len <= 0) goto out;
+        len = qword_get(&mesg, buf, PAGE_SIZE);
+        if (len <= 0)
+                goto out;
 
         err = -ENOENT;
         dom = auth_domain_find(buf);
@@ -537,25 +524,25 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
 
         /* path */
         err = -EINVAL;
-        if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
-                goto out;
-        err = path_lookup(buf, 0, &nd);
-        if (err) goto out_no_path;
+        if ((len = qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
+                goto out1;
+
+        err = kern_path(buf, 0, &exp.ex_path);
+        if (err)
+                goto out1;
 
-        exp.h.flags = 0;
         exp.ex_client = dom;
-        exp.ex_path.mnt = nd.path.mnt;
-        exp.ex_path.dentry = nd.path.dentry;
-        exp.ex_pathname = kstrdup(buf, GFP_KERNEL);
+
         err = -ENOMEM;
+        exp.ex_pathname = kstrdup(buf, GFP_KERNEL);
         if (!exp.ex_pathname)
-                goto out;
+                goto out2;
 
         /* expiry */
         err = -EINVAL;
         exp.h.expiry_time = get_expiry(&mesg);
         if (exp.h.expiry_time == 0)
-                goto out;
+                goto out3;
 
         /* flags */
         err = get_int(&mesg, &an_int);
@@ -563,22 +550,26 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
                 err = 0;
                 set_bit(CACHE_NEGATIVE, &exp.h.flags);
         } else {
-                if (err || an_int < 0) goto out;        
+                if (err || an_int < 0)
+                        goto out3;
                 exp.ex_flags= an_int;
         
                 /* anon uid */
                 err = get_int(&mesg, &an_int);
-                if (err) goto out;
+                if (err)
+                        goto out3;
                 exp.ex_anon_uid= an_int;
 
                 /* anon gid */
                 err = get_int(&mesg, &an_int);
-                if (err) goto out;
+                if (err)
+                        goto out3;
                 exp.ex_anon_gid= an_int;
 
                 /* fsid */
                 err = get_int(&mesg, &an_int);
-                if (err) goto out;
+                if (err)
+                        goto out3;
                 exp.ex_fsid = an_int;
 
                 while ((len = qword_get(&mesg, buf, PAGE_SIZE)) > 0) {
@@ -604,12 +595,13 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
                                  */
                                 break;
                         if (err)
-                                goto out;
+                                goto out4;
                 }
 
-                err = check_export(nd.path.dentry->d_inode, exp.ex_flags,
+                err = check_export(exp.ex_path.dentry->d_inode, exp.ex_flags,
                                    exp.ex_uuid);
-                if (err) goto out;
+                if (err)
+                        goto out4;
         }
 
         expp = svc_export_lookup(&exp);
@@ -622,15 +614,16 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
                 err = -ENOMEM;
         else
                 exp_put(expp);
- out:
+out4:
         nfsd4_fslocs_free(&exp.ex_fslocs);
         kfree(exp.ex_uuid);
+out3:
         kfree(exp.ex_pathname);
-        if (nd.path.dentry)
-                path_put(&nd.path);
- out_no_path:
-        if (dom)
-                auth_domain_put(dom);
+out2:
+        path_put(&exp.ex_path);
+out1:
+        auth_domain_put(dom);
+out:
         kfree(buf);
         return err;
 }